As a surface mounted package, a so-called non-lead package for which extension of leads from a resin package is eliminated, and leads (outer leads) are exposed on a lower surface of the resin package is known.
FIG. 7 is a plan view of a semiconductor device using a non-lead package, and transparently shows, by solid lines, members sealed in a resin package.
The semiconductor device 101 using a non-lead package has a structure for which a semiconductor chip 103 is bonded to a lead frame 102, and these are sealed by a resin package 104. The resin package 104 is formed in a regular square shape in a plan view.
The lead frame 102 includes an island 105 and four leads 106 separated from the island 105. The island 105 is, in a plan view, formed in a regular square shape whose center overlaps the center of the resin package 104 and whose sides are parallel with the sides of the resin package 104. The four leads 106 are each disposed so as to be opposed to each corner portion of the island 105 in a direction along a diagonal of the island 105. Each lead 106 is, in a plan view, formed in a regular square shape whose sides are parallel with the sides of the resin package 104. Lower surfaces of the island 105 and each lead 106 are, as terminals for electrical connection with a substrate on which the semiconductor device 101 is mounted, exposed on a back surface of the resin package 104.
The semiconductor chip 103 shows a substantially regular square shape in a plan view, and is disposed on the island 105 so that its sides are parallel with the sides of the island 105. A back surface of the semiconductor chip 103 is bonded to the island 105 via a conductive bonding material. At corner portions of a front surface of the semiconductor chip 103, pads 107 are formed by exposing a part of internal wiring. Between each pad 107 and the lead 106 opposed to the corner portion of the semiconductor chip 103 at which the pad 107 is formed, a wire 108 is stretched.